Pudendal Nerve Palsy

Damage to the pudendal nerve can occur suddenly as a result of trauma to the pelvic region, prolonged bicycling, fractures, or from falls. The pudendal nerve re-enters the pelvis under the sacrotuberous ligament and gives three branches.

The first branch, the inferior rectal nerve, provides rectal tone and perianal sensation. The second branch, the Perineal Nerve, gives scrotal sensation. The third branch, the dorsal nerve of the penis, give branches to the corpus callosum.

The pudendal nerve arises from S2, S3, and S4. The pudendal nerve carries sensations to the external genitals, the lower rectum, and the perineum.

The symptoms of pudendal nerve palsy can start suddenly or develop over time. Symptoms include the loss of sensation or numbness, burning or stabbing pain, difficulty with bladder and bowel functions, and sexual dysfunction.

Causes of pudendal nerve palsy include prolonged sitting exercises such as bicycling or following fracture table traction—the nerve is compressed between the ischium and the hard object.

Treatment options are typically conservative, as the condition is usually transient and will improve over time. Treatment includes:

• Rest
• Physical therapy
• Stretches and exercises
• Anti-inflammatory medications
• Injections/nerve blocks
• Surgery (as a last resort)

 

Prevention options for bicyclists consists of changing the sitting position while riding the bicycle and changing the seat from a narrow seat to a wider seat.

Unbelievable Bacteria- Part II

Why do open fractures have increased risk for infection?

The presence of bacteria within an open wound increases the risk of colonization when hardware is used. Once the hardware is colonized, the bacteria grows rapidly. During the rapid growth phase, the bacteria secretes a polysaccharide sugar layer, called a “biofilm”, or slime layer that encases the bacteria. This biofilm provides protection to the bacteria against the body’s defenses and antibiotics.

Within the biofilm, there are channels that allow the bacteria to pass nutrients, messaging signals, and even DNA to each other. The bacteria pass on their DNA by:

1. Transformation
2. Transduction
3. Conjugation

Transformation is when a bacterial cell ruptures, releasing its DNA, which is then taken in by another bacteria. Transduction occurs when DNA is transferred from one bacterium to another by a virus. Phage DNA and proteins are made and bacterial chromosomes are broken up, completing the gene transfer. The phage release themselves from the host, carrying either bacterial or phage DNA. Conjugation occurs when two bacteria attach themselves together with a sex pilus and exchange their DNA.

How does the bacteria become resistant to antibiotics?

The bacteria can alter the genes they express by as much as 50-60%. By doing this, the bacteria can produce enzymes such as beta-lactamases, which destroy certain antibiotics before they can reach their target site. They can also make Efflux pumps which expel antibacterial agents from the cell before it can reach its target site. Finally, by expressing different genes, the bacterial cell wall can be altered to no longer contain the binding site of the antibiotic agent. Because the antibiotics cannot break through the biofilm and access the bacteria, the bacterium in the biofilm can become up to a thousand times more resistant to the antibiotics by the different mechanisms previously discussed.

If there is biofilm on the hardware, what can the physician do?

The only proven treatment, is to remove the hardware and wash the wound. However, removal of the hardware is a problem if the fracture is not healed and the fixation is needed. The physician may decide to suppress the infection, leaving the hardware until the fracture has improved. Or, the physician may decide the remove the hardware and seek an alternative method for stabilizing the fracture, such as an external fixator, and then using a biological material to help heal the fracture.

These are the issues that make infection with hardware so complex!

Galeazzi Fracture

Galeazzi Fractures are a type of fracture of the radial shaft which is associated with dislocation of the distal radio-ulnar joint (DRUJ). This particular fracture is name after Ricardo Galeazzi who was an Italian surgeon in Milan. This injury is uncommon and only accounts for about 7% of all forearm fractures in adults.

 

A radius fracture may be short, oblique, or transverse and involves a fractures at the junction of the middle third and distal third of the radius with associated injury to the distal-ulnar joint. The closer the fracture is to the DRUJ, the more likely that it will be unstable. Dislocation of the DRUJ is usually dorsal. It may be associated with either a ligamentous injury or fracture of the styloid process of the ulna.

A fracture is usually located above the proximal border of the pronator quadratus muscle. The distal fragment usually moves towards the ulna. Galeazzi fractures are best treated with open reduction and internal fixation of the radius and assessment of the distal radio-ulnar joint.

Surgery is necessary. Nonsurgical treatment in adults usually results in recurrent dislocations of the distal ulna and a bad outcome. Surgery is done by a volar plate fixation. Followed by assessment of the Distal Radio Ulnar Joint (DRUJ), if stable, the forearm will be splinted in supination for six weeks. If the joint is unstable, reduce and pin the distal radio-ulnar joint in supination for about four weeks. If the joint is not reducible, open and explore the joint. Check for entrapment of the ECU.